Increment to Top

Create a function that returns the total number of steps it takes to transform each element to the maximal element in the array. Each step consists of incrementing a digit by one.

Examples

incrementToTop([3, 4, 5]) ➞ 3
// Maximal element in the array is 5.
// To transform 3 to 5 requires 2 steps: 3 -> 4, 4 -> 5.
// To transform 4 to 5 requires 1 step: 4 -> 5.
// Total steps required is 3.

incrementToTop([4, 3, 4]) ➞ 1
// Maximal element in the array is 4.
// To transform 3 to 4 requires 1 steps: 3 -> 4.
// Total steps required is 1.

incrementToTop([3, 3, 3]) ➞ 0

incrementToTop([3, 10, 3]) ➞ 14

Notes

• If the array contains only the same digits, return 0 (see example #3).
• Bonus: Can you write a solution that achieves this by only traversing the array once? (i.e. without finding the max beforehand)